Monkeys avoid selfish people. A dog tail wag to the left means it's nervous, to the right means pleasure. Elephants, goats and cows all pee for 21 seconds.

Who knew?

Turns out, no one did until 2013.

It was a year of wonderous discoveries and revelations.

And if those weren't enough, we also figured out that there is only one sneeze in the Bible, the Pope used to work as a bouncer and that Cubans use sniffer rabbits instead of sniffer dogs to rescue people.

Perhaps most startling is the realization that McDonald's drive-thrus won't serve people on horseback. Payback came when the horse left staff a steaming present on their floor. McDonald's told the BBC that customers were distressed.

Other revelations include the news that Justin Bieber and Will.I.am used to live next door to each other and that there is water on Mars.

And that's good news for when Justin Bieber becomes just too much and we all have to leave.